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Environmental Chemistry Commons

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Full-Text Articles in Environmental Chemistry

Algal Biomarkers As A Proxy For Pco2: Constraints From Late Quaternary Sapropels In The Eastern Mediterranean, Caitlyn R. Witkowski, Marcel T.J. Van Der Meer, Brian Blais, Jaap S. Sinninghe Damsté, Stefan Schouten Sep 2020

Algal Biomarkers As A Proxy For Pco2: Constraints From Late Quaternary Sapropels In The Eastern Mediterranean, Caitlyn R. Witkowski, Marcel T.J. Van Der Meer, Brian Blais, Jaap S. Sinninghe Damsté, Stefan Schouten

Science and Technology Department Faculty Journal Articles

Records of carbon dioxide concentrations (partial pressure expressed as pCO2) over Earth’s history provide trends that are critical to understand our changing world. To better constrain pCO2 estimations, here we test organic pCO2 proxies against the direct measurements of pCO2 recorded in ice cores. Based on the concept of stable carbon isotopic fractionation due to photosynthetic CO2 fixation (Ɛp), we use the stable carbon isotopic composition (δ13C) of the recently proposed biomarker phytol (from all photoautotrophs), as well as the conventionally used alkenone biomarkers (from specific species) for comparison, to reconstruct pCO2 over several Quaternary …


Leaf Traits Can Be Used To Predict Rates Of Litter Decomposition, Marc Rosenfield, Jennifer L. Funk, Jason K. Keller, Catrina Clausen, Kimberlee Cyphers Jun 2020

Leaf Traits Can Be Used To Predict Rates Of Litter Decomposition, Marc Rosenfield, Jennifer L. Funk, Jason K. Keller, Catrina Clausen, Kimberlee Cyphers

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Strong relationships exist between litter chemistry traits and rates of litter decomposition. However, leaf traits are more commonly found in online trait databases than litter traits and fewer studies have examined how well leaf traits predict litter decomposition rates. Furthermore, while bulk leaf nitrogen (N) content is known to regulate litter decomposition, few studies have explored the importance of N biochemistry fractions, such as protein and amino acid concentration. Here, we decomposed green leaves and naturally senesced leaf litter of nine species representing a wide range of leaf functional traits. We evaluated the ability of traits associated with leaf and …


Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro May 2020

Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro

Honors Scholar Theses

Cancer is a disease that stems from genomic errors that are not corrected properly by cellular repair mechanisms. Errors are more likely to form when organisms are subjected to DNA damage by mutagenic compounds. 1-Nitropyrene, a nitrated polycyclic aromatic hydrocarbon (nitro-PAH), has been shown to be a potent mutagen that causes cancer. Nitro-PAHs can arise from diesel exhaust products in the environment. Out of all nitro-PAHs, 1-nitropyrene is found in largest quantities in the environment. This poses a great need to study its effects biochemically in order to address its toxicity in DNA. Other nitropyrene derivatives, including 1,6-dinitropyrene and 1,8-dinitropyrene, …


385— Optimizing Nitrogen Concentrations To Maximize Lipid Yields For Biodiesel Production, Wady Jacoby, Daria Zhogina, Pavel Ananev, Lauren Saggese, Max Muller, Barnabas Gikonyo Apr 2020

385— Optimizing Nitrogen Concentrations To Maximize Lipid Yields For Biodiesel Production, Wady Jacoby, Daria Zhogina, Pavel Ananev, Lauren Saggese, Max Muller, Barnabas Gikonyo

GREAT Day Posters

Select subspecies of microalgae are considered to be the most promising candidates for third generation renewable resources of biodiesel. Algae not only ingest excess carbon emissions from the atmosphere, they also convert it into energy-dense lipids which can be harvested, and then transformed into biodiesel. However, before the fuel industry can adopt algae farming as a realistic alternative to fossil fuels, the process of harvesting algal lipids must be optimized further. Our research aims to make algal lipid extraction more realistic by determining the ideal growing conditions of the algae species Chlorella Vulgaris. Our research this semester focused on two …


Assessment Of Soil Protein And Refractory Soil Organic Matter Across Two Chronosequences Of Newly Developing Marshes In Coastal Louisiana, Usa, Stuart Alexander Mcclellan Feb 2020

Assessment Of Soil Protein And Refractory Soil Organic Matter Across Two Chronosequences Of Newly Developing Marshes In Coastal Louisiana, Usa, Stuart Alexander Mcclellan

LSU Doctoral Dissertations

The impacts of sea-level rise and hydrologic manipulation are threatening the stability of coastal marshes throughout the world, thereby increasing the potential for re-mineralization of soil organic matter (SOM) in these systems. Such threats have prompted marsh restoration efforts, particularly in coastal Louisiana, yet it is unclear how the slowly decomposing (refractory) and quickly decomposing (labile) fractions of SOM may be differentially affected by different approaches to marsh restoration. Additionally, otherwise labile compounds may accumulate in the soil via a range of protective mechanisms, including rapid burial and association with organic compounds that are thought to enhance soil aggregation, such …